Physical Therapy Assistant Practice Exam 2026 - Free PTA Practice Questions and Study Guide

For gait activities on a level surface, the maximum amount of knee flexion required is approximately 0-60 degrees. During normal walking, the knee flexes to allow for smooth and efficient movement. The initial stance phase involves the knee being nearly straight (0 degrees) as the foot makes contact with the ground. As the person begins to swing their leg forward during the swing phase, the knee flexes to clear the foot off the ground.

Although the knee can flex further, generally beyond 60 degrees, it becomes less necessary for basic walking on level terrain. This degree of flexion is sufficient for the majority of gait mechanics without requiring excessive energy expenditure or compromising stability. Understanding these mechanics helps physical therapy assistants assess and design appropriate rehabilitation programs for individuals recovering from knee injuries, surgical interventions, or other conditions affecting mobility.